If you are getting a 408 error from X-Lite this means you are not receiving any response from the sip registration server that you are attempting to connect to with X-Lite.
There are a number of reasons for this but they could be caused by:
a) Your router
b) Your firewall (most common reason)
1. Try disabling any firewall software you have running on your desktop. Then test to see if it is now working.
2. If the firewall suggestion does not resolve it - You can also try connected directly to your cable/dsl modem and bypass your router to determine if the router is causing this problem.
You could also try disabling the QoS setting on your router which is under Options -> Advanced Menu -> Quality of Service.
Alternatively you could try the following options:
1. Visit the X-Lite Support page: https://support.counterpath.com/hc/en-us and search on this issue to find answers.
2. Macs may be set to only allow installation from Mac Store, Please enable installs in System Preferences -> Security and Privacy -> General Tab
3. If using the free version of X-Lite it could be due to this because it is not the commercial version (as they want payment but you should be able to download a free version to test beforehand). Please find some links below to the free versions:
PC Windows link only: http://www.counterpath.net/X-Lite-Download
Mac link only: http://www.counterpath.com/x-lite-for-mac-download
4. You could try setting up a STUN server to try and get around firewall issues - go to the Topology tab inside Account settings and where you see the server address field enter: stun.crmdomainname.com (please contact our Support Helpdesk if you need to find out the name of the CRM domain).